Hydraulic cushion for sheet-metal presses



Jan. 1, 1929.

1,697,611 F. J. RODE I HYDRAULIC CUSHION FOR SHEET METAL PRESSES i 1927 5 sheets-sheet 1 Jan. 1, 1929. 1,697,611

' F. J. RODE HYDRAULIC CUSHION FOR SHEET METAL FRESSES o a o I 1 2 Z5 6w I I Y 0 6 @i o 69 Jan. 1, 1929. 1 1,697,611 F. J. RODE HYDRAULIC CUSHION FOR SHEET METAL PRESSES 4 .1 4 19% Wheat Jan. 1, 1929. 1 1,697,611

F. J. RODE HYDRAULIC CUSHION FOR SHEET METAL PRESSES- Sheets-Sheet 5 7M6/6 Ja Patented Jan. 1, 1929.

rnnnnion .I. nomror CHICAGO,

ILLINOIS, ASSIGNOR 'ro mnnoun'rrn 'roor. & mo.

COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 01 ILLINOIS.

HYDRAULIC CUSHION FOB SHEET-METAL PRESSES.

Application filed April 9,

. This invention relates to improvements in hydraulic cushions particularly adapted,

though not necessarily limited in its use in sheet metal presses 11). which the metal is shaped by means of co-operating dies, one of which is reciprocable toward and away from the other, the work being clamped or held by means of a blank or work holding ele ment that co-operates with the reciprocable die member, the blank or work holding element being resisted in its movement in one direction by the said cushion, and one of the objects of the invention is to provide an improved cushion of this character in which the blank or work holding element is indirectly acted upon by air pressure from a suitable source, the air pressure acting upon a column of liquid which in turn acts upon the blank or work holding element.

A further object is to provide an improved cushion of this character in which the cushion embodies a cylinder and piston, one of which is mounted stationary, the other being movable in one direction by the pressure of the which timing may be blank or WOl'l' holder under the influence of the reciprocable die and in the other direction by the combined pressure of the air and liquid column, which also serves to return the movable part of the cushion to its normal position.

A further object is to provide in connection with such a cushion a combined valve and timing mechanism which will operate in the exact time as required for the work, and

predetermined and accurately and permanently set or changed at will to suit the particular requirements of the work being operated upon.

It has been found that if air is contained in the liquid within the cylinder whichacts upon the piston to create the resistance pressure, such liquid will be compressible, more or less, according causing the liquid to be spongy, with the result that there will be a rebound or back lash. The piston will then follow the upward stroke of the press which is not desirable. Itis another object of the present invention to relieve the cylinder of such air thereby overcoming the back lash and protecting the work as well as the machinery.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists to the amount of air,

1927. Serial No. 182,434.

in the features of novelty in substantially th construction, combination and arrangement of the several parts hereinafter more fully described and claimed and shown in the accompanying drawings illustrating this invention, and in which Figure 1 is a view partly in elevation, partly in section and partly broken away of a sheet metal press having a cushion constructed in accordance with the principles of this invention applied thereto, and with the parts in the position which they will assume just before the commencement of the shaping of the work.

Figure 2 is an enlarged sectional view taken on line 22, Figure 1, and showing the cushion parts in a different position.

Figure 3 is a detail horizontal sectional view taken on line 3-3, Figure 2.

Figure 4 is a detail view partly in elevation, partly in section and partly roken away, showing the parts in another position with the work being ejected.

Fi re 5 is a view similar to Figure 4, showlng the parts in another position.

Figure 6 is a view similar to Figure 1, showing a modified form of the invention.

Figure 7 is an enlarged detail side elevation of Figure 1, with parts omitted and partly in section. I

Figure 8 is a sectional view on line 8-8, Figure 6. I

Referring more particularly to the draw- Ings the numeral 10 designates generally the bed of the machine, 11 uprights, 12 a reciprocating ram or member, 13- a crank shaft,

14: a link connecting the reciprocating mem-' her to the crank shaft, the shaft being driven 1 in any suitable manner and fro-m any suitable source, preferably through the medium of a pulley 15, having a belt (not shown) applied thereto.

All of the above referred to parts are of the ordinary and well known construction.

Mounted upon the bed of the press is a hollow die member 16 having an opening 1'1 therein surrounded preferably by a curved wall 18.

Arranged beneath the bed plate 10 and su ported in any suitable manner preferab y upon a support 19 that is connected with the bed of' the press by means of hangers 20, is a cylinder 21 in which a piston or plunger 22 is reciprocable. Connected with the plunger ing to cooperate with the reciprocatin 'die 27 I that is in turn connected with the reciprocating member 12 of the press.

Projecting into the cavity of the die 16 are resiliently yielding members 28, the extremities of which are beveled and these members 28 serve as stripper members to strip the shaped article from the die member 27.

Connected with the cylinder 22 and having communication therewith as at 29, preferably through the bottom of the cylinder, is a pipe 30 having upright portions 3132, which portions have communication with each other, and intermediate these portions is a pressure control yalve 33. This valve 33 is held upon its seat by means of a spring 34, the tension of which may be varied by means of an adjusting device 35, so that the degree of pressure which is necessary to unseat the valve 33 by the pressure of the liquid, in a manner to be set forth, may be varied or controlled.

The pipe section 32 has communication.

with a tank or receiver 36, having a fill openin 37 closed by a suitable closure.

luid pressure, such as air is supplied to the tank or receiver 36 by means of a pipe 38 having a manually controlled valve 39 therein and a fluid pressure controlled valve 40.

A by pass 41 is connected with the pipe sections '31--32 and leads around the valve 33. A valve 42, preferably a flap valve, is arranged in the by pass adjacent the pipe section 31 and this valve 42 will be opened by pressure on one side thereof, but will be closed y the pressure on the other side thereof. 7 A valve 43 is also arranged within the by .pass 41 and this valve '43 is adapted to be actuated automatically at predetermined times in the cycle of operation of the press so as to open and close to permit liquid to flow through the by pass 41 at a predeter,

. mined time in the cycle of operation of the press and to close the by pass to prevent liquid from flowingfherethrough.

Any suita le means may be provided for thus operating the valve 43 and a simple and eflicient means embodies a link connection 44 havin a yielding section 45 which is connectecf with a lever 46, which in turn is connected as at 47 with the valve 43. The other end of the link 44 is connected with a crank 48, which in turn is connected with the shaft 13.

- In starting the prex and assuming that there'is no liquid present -in the tank or receiver 36, liquid may be supplied to the tank through the fill opening 37, the valve 43 being first opened. The liquid thus supplied will flow from the tank 36 through the pipe connection 32, by pass 41, around the valve 43,

through the valve 42, through the pipe'sec'tion 31, through the opening 29 and into the cylinder 21 beneath the plunger 22.

When the desired amount of liquid has been supplied, which may be determined by a gauge 49 on the receiver 36, the valve 43 is closed as well as the fill opening 37 Fluid pressure, such as air, is then admitted to the receiver 36 by opening the valve 39. .The fluid pressure in the receiver 36 will,

when the valve 43 is opened, be manifested upon the liquid column 50 to such an extent that it will raise the plunger 22 to cause the blank holding element 26 to assume a position that its upper faces will be substanthe die 16, so-that it will be shaped as shown in Figure 2.

During the lowering movement of the work holder 26 the valve 43 will be closed and the movement of the work holding element 26' will be resisted in its lowering movement by the combined pressure of the liquid 50 and the resistance of the valve 33 upon the plunger 22.

The pressure thus exerted upon the liquid .50 will close the valve 42 to prevent the liq uid from escaping through the by pass 41, and the only means of escape of the liquid from the pipe section 31 and cylinder 21 is through the valve 33. This "alve 33 is set to be operated at a predetermined pressure or such a pressure as is necessary to properly hold or clamp the work 51. When this predetermined pressure is exerted by the plunger 22 upon the liquid 50 the valve 33 will be unsea-ted and the li%1idwill then flow through the pipe section 32,

through the by pa$41being prevented by the valve 43, which will be closed at that time.

It will therefore be manifest that it is 'possible with this device to build up a considerable pressure on the press within a limited space and by means of this cushion a press ackinto the container 36, the escape of the liquid in the pipe section 32 press. I

After the article has been shaped as shown in Figure 2, the blank holding member 26 will be held against return movement by I reason of the fact that the valve 43 will not be. opened to" permit the liquid pressure to act upon the plunger 22 to return the blank holding means the die 27 has receded sufiiciently topermit the work 51 to be stripped from the die 27 and ejected from the die 16.

As the die 27 descends the work 51 will move past the resiliently projecting strippers P 28, the latter then passing over the edge of the shaped article. As the die 27 ascends the work will then be stripped from the die 27 and the work will be ejected from the die 16 through a suitable opening 52 onto a. chute or incline 53'. This ejecting may be accom-= plished in any suitable manner such as by means of an ejector 54 which is connected by means of a pin and slot connection 55, with an arm 56, the latter in turn being connected with a rock shaft 57 having an arm 58 which carries a roller or projection 59. Connected also with the shaft 57'is an arm 60 having a weight 61 thereon, and which weight tends normally to retract the ejector 54 to the position shown in Figure 2.

Connected with thereciprocating member 12 is a depending member 62 which prefer-- ably moves in a guideway 63. A dog 64 having a beveled extremity 65 is pivotally connected as at 6.6 intermediate its ends, with a- Thesupport 67 carried by the member 62. support 67 is provided with a projection 68 adapted to be engaged by an extension 69 on the dog 64, a spring 70 being preferably pro- P vided for normally holding the extension 69 in contact with the projection 68 on the support 67.

This dog 64 is so arranged and operates during its bodily lowering movement to swing about its pivot 66 when the beveled end engages the projection 59 on the arm 58 when the parts are in the position shown in Figure 2. As the dog 64 is lowered it will swing about its pivot so as to pass the projection 69. After it has passed this projection the spring 7 0 will swing the dog about its pivot into the position shown in Figure 2, so that its extremity will project under the projection 59 on the arm 58. When the dog is then raised it will be held against movement about its pivot by reason of the extension 69 engaging the projection 68, with the result that the shaft 57 will be rocked in advance of the ejector 54, so that it will contact with and move the finished article 51- through the opening 52 in the die 16. After to its normal position, until the dog 64 has passed the projection 59 on its upward movement the weight 61 will-return the ejector 54 to its normal position or to the position shown in Figure 2.

With this improved construction it will be;

manifest that the blank or work holding element will be indirectly acted upon by air pressure from any suitable source, the air pressure in turn acting upon a column of liquid, which in turn acts upon the element, and that the pressure is controlled by a timing device so that the liquid pressure may be entirely eliminated at any desired the cycle of operation .of the press.

point in. It is also possible to build up a pressure with a cushion of this character greatly in excess of comressed air devices and especially on presses with limited space, and under dies of small dimensions, built for very heavy work, and often in a very limited space, the timing of the operation of the cushion and the relieving of the pressure thereon being under the control of the will of the operator so that the timing may be predetermined and accurately and permanently set or changed at will.

The pipe 32 is provided witha T head 32 located within the tank or container 36 and communicates with both, the head opcrating as a bafile or deflector so as to deflect the liquid entering the tank through the pipe 32 and preventing the same from spouting upwardly into the tank which would agitate or churn the liquid 50 in the tank. By thus deflecting the liquid as it enters the tank this objection will be overcome.

In the form of the invention shown in Figures 6,7 and 8, there may be provided in the pipe 32 an ordinary expansijonjoint 71, and the pipe 32 is connected directly with the casing of the valve 33, the valve being preferably located adjacent and in close roximity to the bottom of the cylinder 21. The liquid 50, when it is forced out of the cylinder 21 under a predetermined pressure by the plunger. 22, will unseat the valve 33 so that the liquid will flow through the pipe 32 back into the tank or receiver 36.

A branch or by pass pipe 72 leads from the ,pipe 32 to a chamber 73 which is also preferably arranged adjacent and in close proximity to the bottom of .the cylinder 21 and has communication therewith. In this pipe 72 may bev arranged an ordinary expanliquid 50 when forced from the cylinder 21 under pressure Wlll' pass through the pipe 32, after the valve 33 is unseated.

Connected with thechamber 73 is a dome or chamber 76 for receiving air which may be contained in the liquid and which air will be separated from the liquid to pass into the chamber 76. Leading from the chamber 76 is a pipe 77 which has communication with the tank or receiver 36 as at 78 above the level of the liquid 50 in the,

tank 36, so that the air which is thus separated from the liquid will be delivered back into the tank or receiver 36 above the liquid therein.

Arranged in the pipe 78 and at a convenient positionis a valve.7 9 by means of which and the valve 82 is opened.

The pressure upon the air will. then cause it to flow from the chamber 76 through the pipe 77, by pass 81, past the check valve 83 and into the tank or receiver 36. The air will be prevented from flowing by back pressure back into the system by means of the check valve 83.

The valve 43 in this form of. the invention and which is opened and closed at a predetermined time in the cycle of operation of the press by being, as shown in the present exemplification of this invention,-connccted with the crank shaft, is. located in the pipe or by pass 72. q

When it is desired to drop the plunger 22 independently of the operation of the press, all that is necessary is'to open the valve 39 so as to relieve the liquid in the tank or receiver 36 from the air pressure, and then open the valve 79, with the result that the piston or plunger 22 will drop in the"cylinder 21 by reason of the fact that the liquid 50 will then flow ino he chamber 73, dome 76 and pipe '77 In operation and with this form of'the invention, the liquid will flow from the tank 36, through the pipe 32, valve 43, branch or by pass pipe 72, past the valve and into the cylinder 21. p

When pressure is exerted'upon the liquid 50 in the cylinder 21 a pressure sufficient to unseat or open the valve 33 is established and the pressure upon the liquid will cause the valve 75 to remain closed and the liquid will be forced into the valve casing to u seat the valve 33 and will then pass throng 1 the lower ortion ofthe pipe 32, around the valve 43, ack into, the tank or receiver'36. Atthe same time-any air which might be contained in the li uid, in the cylinder 21, will separate from t e liquid and accumulate in the chamber 76 and will flow through the pipe 77 into the tank or receiver 36.

the several parts, within the scope of the claims, without departing from the spirit of this-invention. i

What is claimed as new is z i 1. A pressure cushion for sheet metal presses embodying a work holding element, piston and cylinder members, one of said members resisting the movement of the said element in one direction, a container communicating with said cylinder and providing a liquid column in said cylinder operating upon the last said member, and means operating automatically to relieve the said liquid column of any air contained therein.

2. A pressure cushion for sheet metal presses embodying a work holding element,

piston and cylinder members, one of said members resisting the movement of the said element in one direction, a container communicating with said cylinder and providing a liquid column in said cylinder operating upon the last said member, and air receiving chamber having communication with the cylinder, said chamber providing a means Whereby air contained in the liquid in the cylinder may be separated therefrom, and a communication between the air chamber and the said such separated air may be container whereby delivered into the container.

3. A pressure cushion for sheet metal presses embodying a work holding element, piston and cylinder members, one of said ,members resisting the movement of the said element in one direction, a container communicating with said cylinder and providing a'liquid column in said cylinder operating upon the last said member, an air receiving chamber having communication with the cylinder, said chamber providing a means wherebyair contained in the liquid in the cylinder may be separated therefrom, a communica tion between the air chamber and the said container whereby such separated air may be delivered into the container, and means for controlling at will the last recited communication. r

' 4. A pressure cushion for sheet metal presses embodying a work holding element, piston and cylinder members, one of said members resisting the movement of the said element in one" di unicating wit ing across the liquid inlet and against whichbafile the liquid flows.-

ection, a container com-' 1d cylinder and provid- 'ing a liquid column for creating such resistdie transversely a rock shaft, an arm connected with the rock 5'. A pressure cushion for sheet metal presses embodying a resistance pressure creating cylinder, a liquid container, a conduit forming a communication between the container and cylinder and through which conduit the liquid flows from the cylinder and into the container, the end of the conduit within the container being closed to serve as a baffle for the liquid, there being a lateral outlet opening in the conduit within the container.

6. In combination a hollow djie having a forming chamber, means for shaping an article in the die, there being a discharge opening through the lateral wall of the said chamber, an ejector adapted to be projected into the chamber in a direction across the die to eject the article from said chamber, and means for actuating the ejector.

7. In combination a hollow die having a forming chamber, means for shaping an article in the die, there being a discharge open ing through the lateral wall of the said chamber, an ejector'adapted to be projected into and in a direction across the die to eject the article'from said chamber, a rock shaft connected with the ejector for actuating it, and

means for actuating the rock shaft.

8. In combination a hollow die having a forming chamber, means for shaping an article in the die, there being a discharge opening through the lateral wall of the chamber, an ejector adapted to be projected into the thereof to eject the article,

' shaft, a loose connection between the arm and ticle in the die,

forming an article ejecting-the article,

ejector, and means for rocking the shaft to I actuate the ejector.

9. In combination a hollow die having a forming chamber, means for shaping an arthere being a discharge opening through the lateral wall of the said chamber, an ejector adapted to be projected into the die transversely thereof to eject the article, a rock shaft connected withthe ejector for actuating it, an arm connected with the shaft, means connecting the arm and the ejector, means tending normally to move the shaft in one direction, and means for rocking the shaft against the stress of the last recited means. I

10. In combination a hollow die, means for therein, an ejector for a rock shaft, an operative connection between the shaft and the ejector, means for moving the shaft in one direction, means for moving the shaft in the opposite direction, the last recited means embodying a projection on the shaft, a recip rocable member, a pivot-ally mounted element on said member adapted to contact with said projection tobe moved about its pivot thereby, to pass beneath the 'saidprojection, and means for restraining the said element in its movement about its pivot in the opposite direction whereby the movement of the reciprocable member in one direction will cause the said element to rock the said shaft.

In testimony whereof I have signed my name to this specification, on this 17th day of March, A. D. 1927.

FREDRICH J. RODE. 

